Harmful Algal Blooms, or "HAB's", are linked to many cases of human poisoning each year. Economic losses and costs to the fishing industry, public health, and tourism are estimated to be $40,000,000 annually, as of the late 1990s. 1 such HAB causes paralytic shellfish poisoning (PSP). Following an algal bloom, the toxins released by the microbes may accumulate in filter-feeding shellfish, consumption of which then causes disease symptoms, the most severe of which is respiratory paralysis and death. PSPs are 1 of only a few marine toxins that can be fatal to humans when consumed in food. This proposal seeks funding to develop recently reported technology for the fluorescence detection of PSPs into fluorescent detector plates. In Phase I, the limits of detection of 4 PSPs will be determined, and a preliminary evaluation of fluorescence response in toxic shellfish extracts will be conducted. Such plates will be adapted for use in a portable device in Phase II. The Specific Aims of this project are: 1. Synthesize fluorescent chemosensors suitable for covalent attachment to a glass slide. 2. Self-assembly and covalent attachment of the sensors to glass slides and evaluation of the surface properties and coating. 3. Evaluation of the fluorescence amplification to solutions of saxitoxin, PSP toxins, and toxic shellfish extracts. Paralytic Shellfish Poisons (PSPs) enter the human food chain most commonly through filter-feeding shellfish transvectors. The most toxic PSP, saxitoxin, is also 1 of only 3 "small molecules" on the government's list of "Select Agents". Fast, inexpensive means of detection PSPs is desirable. [unreadable] [unreadable] [unreadable]